Vapochromic films of π-conjugated polymers based on coordination and desorption at hypervalent tin(<scp>iv</scp>)-fused azobenzene compounds
Vapochromic films of π-conjugated polymers based on coordination and desorption at hypervalent tin(<scp>iv</scp>)-fused azobenzene compounds
复制标题
基于高价锡(<scp>iv</scp>)稠合偶氮苯化合物配位和解吸的π-共轭聚合物气色薄膜
DOI：
10.1039/d2qm01295b
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发表时间：
2023
影响因子：
7
通讯作者：
Chujo Yoshiki
中科院分区：
文献类型：
--
作者：
Gon Masayuki;Morisaki Yusuke;Tanimura Kazuya;Tanaka Kazuo;Chujo Yoshiki
本文报道了由高价含锡π共轭聚合物组成的薄膜材料的合成和汽致变色行为。我们制备了溴化锡稠合偶氮苯和具有四甘醇作为侧链的改性芴的共聚物。合成的聚合物具有良好的成膜性和与配位溶剂分子如二甲基亚砜（DMSO）的高亲和力。特别是，当暴露于DMSO蒸气时，我们发现了从蓝色到紫色的明显颜色变化。结果表明，颜色的变化应起源于可逆改变的配位数之间的5和6的高价锡（IV）的偶氮苯化合物中参与的主链共轭。此外，我们还观察到，锡和配位溶剂之间的结合常数可以通过锡原子上的两个取代基的影响，并随后通过改变取代基的类型调制薄膜中的蒸发光致变色的响应度。此外，颜色的变化行为可以通过量子计算与密度泛函理论估计。我们不仅证明了超价锡可以作为开关单元来调节溶剂配位引发的π共轭聚合物的电子结构，而且还证明了通过理论计算来估计超价锡与溶剂分子之间的亲和力可以预测薄膜中的汽致变色行为。
We report the synthesis and vapochromic behaviors of film materials consisting of hypervalent tin-containing π-conjugated polymers. We prepared copolymers with brominated tin-fused azobenzenes and modified fluorene having tetraethylene glycol as a side chain. The synthesized polymers showed good film-formability and high affinity with coordinating solvent molecules such as dimethyl sulfoxide (DMSO). In particular, we discovered distinct color changes from blue to purple when exposed to DMSO vapor. It was revealed that color changes should originate from reversible alteration of the coordination-number between five and six of hypervalent tin(IV) in the azobenzene compounds involved in the main-chain conjugation. Moreover, we also observed that binding constants between tin and coordinating solvents could be influenced by two substitutions on the tin atom and subsequently modulated responsivity of vapochromism in films by altering the type of substituent. Furthermore, the color-change behaviors can be estimated by quantum calculations with density functional theory. We demonstrate not only that hypervalent tin can work as a switching unit for modulating the electronic structures of π-conjugated polymers triggered by solvent coordination but also that vapochromic behaviors in films can be predicted by estimating the affinity between hypervalent tin and solvent molecules with theoretical calculations.